The conventional air-spring flexible members are provided for higher loads in larger motor vehicles and are provided with sealing beads having form-rigid core rings embedded therein. Compared to these conventional air-spring flexible members, the sleeve-type flexible members afford the advantage of being especially inexpensive to manufacture and the possibility is provided to produce the same by a simple mechanical separation from longer lengths of the flexible members. The sleeve-type flexible members are provided primarily for use in automobiles. The end sections of the sleeve-type flexible member are of the same size and are attached to respective connecting parts mounted on the chassis and motor vehicle axle assembly, respectively. Continuous, radially plastically deformable clamping rings for clamping the end sections to these connecting parts have been proven in use. The end sections of the sleeve-type flexible members are clamped in friction-tight engagement by the radial deformation of the clamping rings.
The pull-out force of the sleeve-type flexible member is limited by the frictional resistance of the clamped end sections. It is possible that the end sections are slowly pulled out of the clamp during operation of the motor vehicle which would constitute a failure of the air spring.
Published European patent application 0,151,696 discloses that a higher pull-out force of the clamped end section can be obtained in that one end section of the sleeve-type flexible member is pushed over a stub-shaped projection which is provided with circular peripheral ribs. These peripheral ribs penetrate into the elastically yieldable wall of the flexible member under the influence of the radially inwardly directed pressing force of the deformed clamping ring pushed thereover so that the frictional-resistive effective clamping is additionally augmented by a form-tight engagement in the wall of the sleeve-type flexible member. The pull-out force is increased by means of this configuration. However, too great a pressing force applied by the radially deformed clamping ring on the end section of the sleeve-type flexible member can be disadvantageous since it can lead to damage of the elastomeric material and the reinforcement layers. The pressing force becomes too great because of different manufacturing tolerances.